Plant Uptake Of Soil Cu/Zn Under Chelates Induction Together With A Vertical Direct-current Electrical Field And Its Efficient Control Of Leaching Risk Of Cu/Zn Complexes

This thesis investigated the migration of metal-complexes in soil column and plant uptake of soil Cu and Zn through use of vertical electrical field. Firstly, the migration of Cu- and Zn-EDTA in a soil column(1.85 kg) loaded with a Cu, Zn contaminated soil induced by EDTA was investigated in terms of the direction and magnitude of a vertical electric field applied. Secondly, greenhouse pot experiments (5 kg) were performed to examine ryegrass uptake of soil Cu and Zn and their leaching as affected by vertical electric field and/or EDTA application. Thirdly, the real control effect of the migration of metal complexes in a large soil column (23 kg) during EDTA/EDDS induced phytoremediation with vertical direct-current electrical field was examined. Main results are listed as follows.1. Migration of Cu- and Zn-EDTA in a soil column loaded with a Cu, Zn contaminated soil induced by EDTA was investigated in terms of the direction and magnitude of a vertical electric field applied. The results show that migration behaviors of Cu- and Zn-EDTA in the soil column changed with the applied electric fields. When the anode was arranged in the upper soil column, the migration of Cu- and Zn-EDTA to the lower column was significantly reduced, and the Cu and Zn concentrations in the lower soil column decreased, but vice verse in the upper soil column with a high concentrations of Cu and Zn, which were markedly higher than that without electric field applied. However, when the cathode was arranged in the upper soil column, the migration of Cu-, Zn-EDTA to lower soil column was enhanced and the complexes accumulated there. Compared to the control, electrokinetic effects changed distribution of the total Cu,Zn in soil column and physicochemical properties of the soil near electrode.2. Greenhouse pot experiments were performed to examine ryegrass uptake of soil Cu and Zn and their leaching as affected by vertical electric field and/or EDTA application. The results show that, when a vertical electric field was applied, the shoot Cu concentration...